When the Champions League draw was made back in December, common wisdom said that Atletico Madrid would comfortably progress to the Quarter Finals. The Spanish side were then, as they are now, quickly providing the first true challenge to the Real Madrid-Barcelona duopoly of La Liga, while Milan were floundering in Serie A.

The Rossoneri won just four league games before the winter break, which led to Massimiliano Allegri losing his job and former Milan midfielder Clarence Seedorf taking charge. That they ended up as Italy’s sole representatives in Europe’s elite competition was seen as something of an anomaly in an otherwise abysmal first half of the season.

Since then, however, the former Netherlands international’s presence on the bench has seen morale around the club lift immeasurably. Now, thanks to his implementation of a clearly defined system—and the absence of some previously maligned players—there is something of a belief in the San Siro outfit once again.

Not everything has been perfect, yet the progress is clear to see. Seven points from Seedorf’s three games as coach included their first back-to-back league wins of the campaign, and their only loss was to third place Napoli earlier this month.

Last weekend they followed that up with a win against Bologna, and once again the rediscovered belief was clearly evident. Still missing one or two key figures—including Stephan El Shaarawy—Milan have only recorded one clean sheet, and there is still much for Seedorf to work on in order to get them once again challenging for honours.

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Yet, as the first leg unfolded at the famous old stadium on Wednesday night, the home side gave a performance which would have been almost unthinkable when their plastic ball was drawn out in Nyon. The fact the eventual loss by a single goal was widely regarded as “unlucky” (h/t FootballItalia) is testament to their rapid improvement since dispensing with Allegri’s services.

“We put in a great performance, tactically almost perfect,” Adel Taarabt told Sky Italia (via FootballItalia), and it was impossible to argue with his analysis. For the first time, Seedorf began a game without his now customary 4-2-3-1 formation, the Rossoneri coach instead looking to stifle Atleti with a far more defensive 4-3-1-2 framework.

With Andrea Poli behind Kaka and Mario Balotelli, Nigel deJong and Michael Essien provided a sound defensive shield, which also enjoyed 52 percent possession, according to stats site WhoScored. That was essential as—despite their squad containing some very good players—the back line is the area in most need of attention.

They hit the woodwork twice early in the second half; Kaka in particular, unfortunate to see his shot rebound off the crossbar after just 14 minutes. Thibaut Courtois’ superb fingertip save from Poli was crucial while Kaka once again found only the frame of the goal with the keeper stranded.

A tackle from Raul Garcia on Poli saw passionate appeals for a penalty for Milan, and Daniele Bonera summed the game up perfectly when he spoke to Mediaset Premium at fulltime. "We have nothing to be ashamed of," the defender said (h/t Goal.com). "We deserved the lead in the first half and got punished on a set piece after the break. We did everything possible to win this game."

A superb attacking display from Balotelli was vital in helping them enjoy more chances than the visitors, taking 13 efforts to their 10, but Diego Costa would eventually make them pay for their profligacy.

As has been the case all season, a corner in the 83rd minute was not defended properly, and the 25-year-old was allowed a free header at the back post. Milan substitute Ignazio Abate could only flick the ball on, and the striker got in front of AdilRami to steer it into the back of the net.

In three weeks time, as they travel to the Spanish capital, Milan will hope both their luck and their form continues to improve. “The Calderon is a fiery atmosphere,” former Real Madrid midfielder Seedorf told Sky Italia. “But that stadium knows me too. I had some good times there!”